Question

- Starting from the cyclostomes, describe the major innovations that led to the type of endoskeleton seen in tetrapods?

-In addition to hair, many mammals have other keratin outgrowths, including horn sheaths, nails, claws and hooves. Bull horns are unbranched, bony outgrowths, covered with a keratin sheath and are only found in the cow family. Compare these to antlers, which are bony outgrowths only found in the deer family . They lack keratin sheaths and are typically branched. The other big difference is that antlers are shed every year, but horns continue to grow throughout the animal’s life. Think about what deer use antlers for (Hint: they’re almost always only found on males). Based on that, what’s the advantage to being branched?

Answer 1

1. The bony structures in organisms are called as Antlers .
2. They are generally made up of calcium,p hosphorous and are deciduous.
3. The antler growth occurs in males as its production is controlled by an hormone called as testosterone
4. During the growth perikd they are abundant with blood vessels and nerve and hence form an hairy form of structure giving an velvet occurence.
5. They play an important role during the breeding season to attract females and fight against the other male opponents.